DESCRIPTION: (Applicant's Abstract) This is the continuation and expansion of a study (RO1 DA11324) examining the practicality, safety, and clinical efficacy of the office based prescription of methadone by primary care practitioners. The current study population consists of a cohort of 150 women drawn from our Methadone program and randomly assigned to office based prescribing (OBP) or usual care in Methadone Maintenance Treatment Programs (MMTP). At 12 months follow-up, we have found that OBP produces equivalent treatment retention and reductions in illicit drug use, compared to the controls in MMTP. Over 50% of our 12,000 current MMTP patients meet the eligibility criteria for OBP-at least 6 months in MMTP, a stable dose of methadone, and some "take home" privileges. As was found in prior observational studies outside the U .S., it appears feasible to integrate methadone prescribing into office-based medical practice. In the continuation of this study, we propose to follow the current cohort of 150 women for an additional 24 months (for a total of 36 months), to "crossover" 50% of the female controls into OBP, and to add 100 male patients to the randomized design (50 OBP and 50 MMTP). By increasing the size and diversity of the cohort and following them for a total of 3 years, we will both increase the generalizability of our preliminary findings. We will initiate a health services component to study the integration of methadone prescribing within routine medical practice-evaluating patient and provider experiences and satisfaction, the patients' utilization and costs of primary and specialty medical care (with special attention to Hepatitis C, HIV/AIDS, and menopause). Secondary outcome measures (subsidiary or pilot studies) will continue to examine evidence of the use of other drugs (e.g., cocaine), and social adjustment (i.e. work home, criminal activity) In addition, as part of our exploration of alternative models of Methadone treatment, we propose to conduct a pilot study of community pharmacy dispensing of methadone for a sub- group of 20 stable patients (in both OBP and MMTP) who have been in the study for at least 12 month. Both the sponsoring medical institutions' methadone and medical care programs and the group of 15 primary care and specialist physicians currently prescribing Methadone and providing medical care for these patients have agreed to continue participating in the study and to expanding the number of patients.